"Retardation of Experimental Tumorigenesis and Reduction in DNA Adducts by
Tumeric and Curcumin"

Abstract:

Tumeric and its active principle curcumin have been extensively
investigated for their antimutagenic and antioxidant effects in bacteria
and animal systems. Because oral cancers are common in India, an
experimental model of 7,12-dimethylbenzanthracene-induced buccal pouch
tumors in Syrians Golden hamsters was used to evaluate the tumor
retardation effects of turmeric and curcumin. Turmeric and/or curcumin was
administered in the diet and/or applied locally for 14 weeks along with
7,12-dimethylbenzanthracene. After the experimental period, the animals
were sacrificed and oral pouches were examined for tumor number and size.
DNA adducts were estimated by 32P postlabel assay in the cheek pouches.
Neoplastic changes were graded by histopathology. The results of the study
suggest that turmeric or curcumin in the diet and/or applied locally
significantly reduced DNA adducts at the target site. Tumor number and
tumor burden were significantly lower (p<0.05) in the animals that recieved
tumeric in the diet and applied locally. The histopathological examinations
suggested that the neoplastic grading was least in the animals fed or
painted with curcumin (p<0.05). The current study demonstrates that
turmeric or curcumin administered in the diet or applied as paint may have
a plausible chemopreventive effect on oral precancerous lesions.

Additional note:

The dietary dosage used was 1% for turmeric, and 0.03% for curcumin,
which is the yellow pigment in tumeric. A human consuming about 2500
calories daily of the rodent chow would ingest roughly 6 grams of turmeric
or 200 mg of curcumin.